diff --git a/fml/src/main/java/net/minecraftforge/fml/common/DummyModContainer.java b/fml/src/main/java/net/minecraftforge/fml/common/DummyModContainer.java
index d2c567ff0..88b171c36 100644
--- a/fml/src/main/java/net/minecraftforge/fml/common/DummyModContainer.java
+++ b/fml/src/main/java/net/minecraftforge/fml/common/DummyModContainer.java
@@ -200,4 +200,10 @@ public class DummyModContainer implements ModContainer
     {
         return ImmutableList.of();
     }
+
+    @Override
+    public boolean shouldLoadInEnvironment()
+    {
+        return true;
+    }
 }
diff --git a/fml/src/main/java/net/minecraftforge/fml/common/FMLModContainer.java b/fml/src/main/java/net/minecraftforge/fml/common/FMLModContainer.java
index e4e6ae441..1b6bb1914 100644
--- a/fml/src/main/java/net/minecraftforge/fml/common/FMLModContainer.java
+++ b/fml/src/main/java/net/minecraftforge/fml/common/FMLModContainer.java
@@ -39,6 +39,7 @@ import net.minecraftforge.fml.common.versioning.ArtifactVersion;
 import net.minecraftforge.fml.common.versioning.DefaultArtifactVersion;
 import net.minecraftforge.fml.common.versioning.VersionParser;
 import net.minecraftforge.fml.common.versioning.VersionRange;
+import net.minecraftforge.fml.relauncher.Side;
 
 import org.apache.logging.log4j.Level;
 
@@ -611,4 +612,30 @@ public class FMLModContainer implements ModContainer
     {
         return candidate.getContainedPackages();
     }
+
+    @Override
+    public boolean shouldLoadInEnvironment()
+    {
+        boolean clientSideOnly = (Boolean)this.descriptor.get("clientSideOnly");
+        boolean serverSideOnly = (Boolean)this.descriptor.get("serverSideOnly");
+
+        if (clientSideOnly && serverSideOnly)
+            throw new RuntimeException("Mod annotation claims to be both client and server side only!");
+
+        Side side = FMLCommonHandler.instance().getSide();
+
+        if (clientSideOnly && side != Side.CLIENT)
+        {
+            FMLLog.info("Disabling mod %d it is client side only.", getModId());
+            return false;
+        }
+
+        if (serverSideOnly && side != Side.SERVER)
+        {
+            FMLLog.info("Disabling mod %d it is server side only.", getModId());
+            return false;
+        }
+
+        return true;
+    }
 }
diff --git a/fml/src/main/java/net/minecraftforge/fml/common/InjectedModContainer.java b/fml/src/main/java/net/minecraftforge/fml/common/InjectedModContainer.java
index f5e6e8d56..af91db153 100644
--- a/fml/src/main/java/net/minecraftforge/fml/common/InjectedModContainer.java
+++ b/fml/src/main/java/net/minecraftforge/fml/common/InjectedModContainer.java
@@ -201,4 +201,10 @@ public class InjectedModContainer implements ModContainer
     {
         return wrappedContainer.getOwnedPackages();
     }
+
+    @Override
+    public boolean shouldLoadInEnvironment()
+    {
+        return true;
+    }
 }
diff --git a/fml/src/main/java/net/minecraftforge/fml/common/Mod.java b/fml/src/main/java/net/minecraftforge/fml/common/Mod.java
index de2925556..ac51b406a 100644
--- a/fml/src/main/java/net/minecraftforge/fml/common/Mod.java
+++ b/fml/src/main/java/net/minecraftforge/fml/common/Mod.java
@@ -89,9 +89,22 @@ public @interface Mod
      */
     boolean useMetadata() default false;
 
+    /**
+     * If true, this mod will not be loaded on the Dedicated Server environment.
+     * Will crash if both serverSideOnly and clientSideOnly are set to true.
+     */
+    boolean clientSideOnly() default false;
+
+    /**
+     * If true, this mod will not be loaded on the Client environment.
+     * Will crash if both serverSideOnly and clientSideOnly are set to true.
+     */
+    boolean serverSideOnly() default false;
+
     /**
      * The acceptable range of minecraft versions that this mod will load and run in
-     * The default ("empty string") indicates that only the current minecraft version is acceptable.
+     * The default ("empty string") indicates that the currently RUNNING minecraft version is acceptable.
+     * This means ANY version that the end user adds the mod to. Modders PLEASS set this.
      * FML will refuse to run with an error if the minecraft version is not in this range across all mods.
      * @return A version range as specified by the maven version range specification or the empty string
      */
diff --git a/fml/src/main/java/net/minecraftforge/fml/common/ModContainer.java b/fml/src/main/java/net/minecraftforge/fml/common/ModContainer.java
index 984b89993..dde8ddef5 100644
--- a/fml/src/main/java/net/minecraftforge/fml/common/ModContainer.java
+++ b/fml/src/main/java/net/minecraftforge/fml/common/ModContainer.java
@@ -147,4 +147,6 @@ public interface ModContainer
     String getGuiClassName();
 
     List<String> getOwnedPackages();
+
+    boolean shouldLoadInEnvironment();
 }
diff --git a/fml/src/main/java/net/minecraftforge/fml/common/ModContainerFactory.java b/fml/src/main/java/net/minecraftforge/fml/common/ModContainerFactory.java
index db2cd064e..6b1a1240a 100644
--- a/fml/src/main/java/net/minecraftforge/fml/common/ModContainerFactory.java
+++ b/fml/src/main/java/net/minecraftforge/fml/common/ModContainerFactory.java
@@ -32,7 +32,7 @@ public class ModContainerFactory
     public static Map<Type, Constructor<? extends ModContainer>> modTypes = Maps.newHashMap();
     private static Pattern modClass = Pattern.compile(".*(\\.|)(mod\\_[^\\s$]+)$");
     private static ModContainerFactory INSTANCE = new ModContainerFactory();
-    
+
     private ModContainerFactory() {
         // We always know about Mod type
         registerContainerType(Type.getType(Mod.class), FMLModContainer.class);
@@ -40,7 +40,7 @@ public class ModContainerFactory
     public static ModContainerFactory instance() {
         return INSTANCE;
     }
-    
+
     public void registerContainerType(Type type, Class<? extends ModContainer> container)
     {
         try {
@@ -76,7 +76,13 @@ public class ModContainerFactory
             {
                 FMLLog.fine("Identified a mod of type %s (%s) - loading", ann.getASMType(), className);
                 try {
-                    return modTypes.get(ann.getASMType()).newInstance(className, container, ann.getValues());
+                    ModContainer ret = modTypes.get(ann.getASMType()).newInstance(className, container, ann.getValues());
+                    if (!ret.shouldLoadInEnvironment())
+                    {
+                        FMLLog.fine("Skipping mod %s, container opted to not load.", className);
+                        return null;
+                    }
+                    return ret;
                 } catch (Exception e) {
                     FMLLog.log(Level.ERROR, e, "Unable to construct %s container", ann.getASMType().getClassName());
                     return null;